Which planet in the Solar System was born first?

Despite being the "youngest", our Earth has the most ideal living conditions among the 8 planets, partly thanks to the "support" from giant planets that formed tens of millions of years before it - Photo: NASA

The sun was born first

About 4.5 billion years ago, a giant cloud of gas in space collapsed under gravity and gave birth to the Sun, the central star of the planetary system in which we live.

The remaining gas and dust did not disappear, but spread out into a disk of material that orbited the Sun. Within that disk, small dust particles began to collide, stick together, grow into rocks, and then into objects large enough to become planets. This process is called accretion .

When the Sun was young, there was a temperature boundary in its disk where gas and water could freeze, called the snow line . This boundary was located about halfway between the present-day locations of Mars and Jupiter .

Outside the ice line , matter has more ice, which easily condenses into giant planets such as Jupiter, Saturn, Uranus, and Neptune .

Inside the ice line there was less snow, gas and dust so planets like Mercury, Venus, Earth, Mars formed more slowly, and were smaller.

The sequence of the birth of the planets

Based on computational models and observations from telescopes, astronomers believe that Jupiter and Saturn are the two earliest planets to form, just a few million years after the Sun appeared.

Next are Uranus and Neptune , within about 10 million years.

The inner planets, including Earth, took at least 100 million years to complete.

That is, the distant giant planets are the "big brothers" , and Earth is the "youngest brother" of this planetary system.

Although nearly 90 million years apart, in the scale of the universe, that is just "a blink of an eye", less than 1% of the age of the universe.

The planet also "migrates"

Even more interesting, planets do not “stay still” from birth. After forming, they move , some planets moving closer to the Sun, others drifting away, before settling in the position they have today.

Jupiter once moved closer to the Sun, pulling in several small planets and pushing many asteroids away or into the asteroid belt. Neptune also pushed millions of small objects to the edge of the Solar System, creating the Kuiper Belt, home to dwarf planets like Pluto.

Importantly, thanks to Jupiter's gravity and orbit, Earth has been "pushed" into the habitable zone (Goldilocks Zone), not too hot, not too cold, with enough conditions for liquid water to exist and life to appear.

Without Jupiter, Earth would likely be located elsewhere, and life as we know it today… might not exist.

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MINH HAI

Source: https://tuoitre.vn/hanh-tinh-nao-trong-he-mat-troi-duoc-sinh-ra-truoc-20250521203901639.htm